Special Sage Tan

Sage Tan Song Yen, at age 4
Sage Tan Song Yen, a little bundle of joy who weighed 2.5kg when he was born on Dec 25 2005, seemed normal just like his older brother who was born 5 years before.  When he was brought home, his mother noticed that he was hardly awake and at night, he cried a lot and refused his feeds.

Throughout the next week, baby Sage slept all the time even during the din made by the family's barking dogs.  His mother, Cindy Tan, from Johor Baru, had moved to live and work in Singapore after marrying Singaporean, Thomas Tan.

Every child had different habits so Cindy and Thomas, both 38, thought Sage was just a sleepy baby who enjoyed sleeping more.  Since Sage was their second child, they were quite relaxed about his drowsiness and poor appetite.  Little did they know that his condition was very serious.

Poem written by Sage's mum in his 4th birthday invitation
When 13-day-old Sage's condition did not improve, they took him to Singapore's Thomson Medical Centre where his pediatrician warded him immediately because tests showed that he was almost in a coma.  At first, doctors suspected that it was a viral infection, but a battery of tests and scans drew a blank.

They realised that it could possibly be a genetic metabolic disease and decided to transfer Sage to the National University Hospital where Dr Denise Goh, head of the genetics division, carried out more tests.

The Tans still remember the exact words that Dr Goh said which changed their lives forever.

After telling them to sit down, she said: "I have good news and bad news. The good news is I think I know what it is. The bad news is it's not good."
Dr Goh held up a vial of yellow liquid and asked the parents to smell it.  It was a sample of their son's urine and it had a distinctive sweet smell like maple syrup because he has a rare genetic disorder called Maple Syrup Urine Disease (MSUD).

This rare disease causes difficulties in breaking down three types of amino acids -- leucine, isoleucine and valine -- which are essential for normal growth.

Sage celebrating 4th birthday with
his parents and brother, Basil
In MSUD patients who are untreated, these amino acids will build up to toxic levels that can result in brain damage, or even death.  With his leucine levels built up to 12 times its normal level, Sage needed to have his blood cleansed immediately, but he couldn't undergo dialysis because his tiny veins were too small even for the smallest catheter.

Instead, Sage went through a delicate procedure to have his blood drawn out manually, syringe by syringe, and received transfused blood from another syringe over a 4-hour period.

Sage is the first classic case of MSUD in Singapore and with such a rare and difficult-to-manage condition, Sage stayed in the hospital for long periods of time.  To stay alive, he had to be on a very strict low-protein diet with a milk formula specially brought in from the United Kingdom.

To complicate his condition, he had a hyperactive airway and bad gastric reflux and his protein and calories intake had to be constantly monitored and measured with regular blood tests. 

This special milk formula was not available in Singapore but could be obtained in Kuala Lumpur and only with a doctor's prescription.

When the shipment of their order from the manufacturer in the United Kingdom was delayed due to miscommunication, the family was frantic and they had to do all they could to get it from Kuala Lumpur. With the help of Cindy's family and the convenient North-South Highway, two family members synchronised their drive to meet at toll gates by night and delivered one can of this special formula to ensure that Sage could have his meals.

At that time, the nearest lab equipped to provide Sage's blood test results was in Hospital Kuala Lumpur (HKL) because the machine in Singapore had broken down and needed repairs.  If Sage was unwell, he was monitored closer and blood tests were necessary every 3 or 4 days until his amino acid levels were close to normal.

This was an extremely anxious time and they again used what they fondly call the "Tan Express Courier Service", because rushing his blood to HKL by road was a faster alternative than sending to other labs in the United States.  When Sage was 45 days' old, he had spent 34 days in the hospital.

On Feb 7, 2006, Sage was finally home again and it was a whole new experience for the Tans as they were on their own and had to accurately weigh and measure the 6 different components that go into making his milk and manage his daily milk and food intake.

Over time, they learnt how to watch him clinically to observe if there were any symptoms of imbalance in diet because even though blood tests were the best indicator, it couldn't be done everyday.

After Sage celebrated his second birthday in December 2007, he was again hospitalised with stomach flu and suffered frequent seizures with brain swelling that may result in mental disabilities and delayed development.

This started a serious discussion on the possibility of a liver transplant and it culminated with a decision during the Chinese New Year of 2008.  It was a tough decision to make as risks were high and very few such operations were done on MSUD patients in the last 10 years.

After a series of tests, a blood match was found in Sage's cousin, 25-year old Kelvin Tan, and on April 5, 2009, Sage underwent his first liver transplant operation in NUH Singapore.

Although there were some complications to the liver's hepatic artery during the operation, the transplanted liver functioned well and Sage no longer needed to go on a restricted diet.  However, due to clots in the hepatic artery, Sage's bile ducts were seriously blocked and this caused jaundice.

With the threat of liver failure, the Tans sought another liver transplant and Sage was on top priority to find a suitable match. With no match found after 4 months, Cindy's older sister, Ivy, a mother of 3 young children volunteered to donate.

Tests showed that she was a perfect match and with the Tans fully aware that the donor risked herself to give hope to Sage, the operation was completed successfully on Oct 12, 2009.

As a direct consequence of Sage's landmark case, a pilot programme to screen babies for rare genetic disorders was established in Singapore's private and public hospitals in 2007 and today, thousands of babies are being tested for early detection and treatment.

On Dec 25, 2009, the entire Tan family came together in Johor Baru to celebrate Sage's 4th birthday and they also enjoyed a memorable family reunion during the recent Chinese New Year celebration.

For the Tans, it has been a long and at times, tiring journey but they have grown and learnt so much from special Sage, their brave little fighter.

A version of this article was published in The New Straits Times, Johor Buzz on 21 March 2010

Additional Info from Wikipedia, the free encyclopedia

What is Maple Syrup Urine Disease?

Maple Syrup Urine Disease (MSUD) also called branched-chain ketoaciduria is an autosomal recessive metabolic disorder affecting the branched-chain amino acids.  An autosome is a chromosome and in humans, there are 22 pairs of autosomes in addition to the X and Y sex chromosomes.  MSUD is caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex, leading to a buildup of branched-chain amino acids (leucine, isoleucine and valine) and their toxic by-products in the blood and urine.

In an infant, this disease is characterized by the presence of sweet-smelling urine, an odour similar to that of maple syrup.  Infants with this disease at birth seem healthy but if left untreated, will suffer brain damage and eventually die.  The early infancy symptoms include poor feeding, vomiting, dehydration, lethargy and seizures before falling into a coma and going into neurological decline.

MSUD is the most common inborn error of metabolism which affects approximately 1 out of 180,000 infants and has also been reported among Malaysian children.  So newborn screening, early diagnosis and appropriate management would save the children and prevent mental retardation and physical handicaps.  The most common and severe form of MSUD is the classic type which appears soon after birth and requires careful blood chemistry monitoring, a special diet and frequent blood tests to keep the disorder under control.  

With proper diet management, people with this condition that cannot digest meat, eggs, milk, nuts and beans, are able to live healthy, normal lives and not suffer any severe neurological damage associated with this disease.  So a simple pin-prick on the heel of newborn babies for a blood test may change their lives if a genetic disorder was detected early because treatment will generally be futile when a child reached age 7.  The newborn screening technology provided by Kuala Lumpur General Hospital is reputed to be among the best in South East Asia. 

Sage Tan with his Aunty Irene a k a Aunty Bear-bear
Info Update:

Sage's Aunty Irene informed me that he was accepted into full-time kindergarten in February 2011. 

1 comment:

  1. Glad that your child is fine now, we hope that he will grow strong and healthy. Very inspiring story. Mums love really has no bound.